Data centers may host applications and store large amounts of data for an organization or multiple organizations. An enterprise data center or “cloud” may be privately owned and discretely provide services for a number of customers, with each customer using data center resources by way of private networks. In addition, these data centers provide server and desktop virtualization that is dramatically changing the enterprise network by creating many “virtual networks” which connect virtual machines and the physical networks through virtual switches.
When an enterprise data center starts to run out of capacity, the enterprise cloud operator may opt to buy more hardware, which permanently increases hardware and operational costs. Another solution for increasing capacity is to “borrow” or lease resources from a public cloud data center, thereby only temporarily increasing data center costs during the lease period. When the enterprise data center leases capacity from a public or cloud data center, the combination of the enterprise cloud and public cloud is referred to as a “hybrid” cloud. The hybrid cloud is achieved by way of an overlay network.